This invention relates to a system and apparatus for applying sealant, such as tissue sealant, to a work surface, such as biological tissue.
Mixing and/or applying sealant to work surfaces has application in a variety of settings. In the medical field, sealant in the form of tissue sealants have been applied to human and animal tissue, for example, to seal or repair tissue at a surgical or wound site, to stop bleeding, seal wounds, treat burns or skin grafts and a variety of other purposes.
In the medical field, tissue sealant has typically been applied by a syringe-type applicator that ejects tissue sealant directly onto the tissue. Examples of such applicators are shown in U.S. Pat. Nos. 4,846,405, 5,582,596, 5,665,067, 6,461,361 and 6,585,696, and PCT Publication No. WO 96/39212, all of which are incorporated herein by reference. Further examples of such applicators also are sold under the Tissomat and Duploject trademarks, which are marketed by Baxter AG.
The tissue sealant employed in treating biological tissue is typically made of one or more components, such as biocompatible compounds that can be absorbed by the body and do not require later removal from the patient. One example of a known tissue sealant is made of fibrinogen and thrombin. The tissue sealant may be contained in more than one container which can be mixed into an adhesive combination upon ejection from the tissue sealant applicator. For example, the components may exit from two separate outlets positioned in proximity with one another so that these components are mixed to create an adhesive tissue sealant upon ejection from the applicator.
Tissue sealant applicators also may provide tissue sealant that is atomized by means of pressurized, sterile gas such as, for example, air, to form a spray which is a combination of tissue sealant and a sterile gas or air. The applicator is connected to an air or gas source by tubing that supplies the gas or air to the distal end of the applicator in the vicinity of the outlets of the one or more tissue sealant components. For example, gas may communicate with one or more of the tissue sealant components within a mixing area defined by the applicator. Alternatively, the gas may mix with the tissue sealant components after ejection from the applicator. In the latter scheme, the gas or air outlet preferably is located in close proximity to the outlets of one or more of the tissue sealant components and may, for example, be in the form of an annular shaped outlet which surrounds at least one of the tissue sealant component outlets. The result is that the tissue sealant discharges in the form of an aerosol or spray.
The supply of gas or air is preferably coordinated so that, for example, gas is essentially simultaneously supplied to the applicator upon ejection of tissue sealant. However, synchronizing the timing of this supply with the ejection of tissue sealant or its components has proven awkward and difficult, particularly where multiple tissue sealant components are used.
Conventional tissue sealant applicators have relied on the user, such as a surgeon or hospital staff member, to simultaneously activate the supply of gas with the ejection of tissue sealant with separate motions. For example, the user is required to manually turn on and off the supply of gas, such as by foot actuation, in addition to the separate movement required to manually eject tissue sealant or components, such as, for example, by pressing on a syringe plunger or the like. It has proven difficult for the user to coordinate the timing of these two separate motions. Therefore, it is desired to provide a tissue sealant applicator which simplifies activation of a spray discharge of tissue sealant and which further provides a reliable and continuous spray discharge of tissue sealant.